The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 18, 2002
Filed:
Apr. 28, 1997
Peter Matic, Alexandria, VA (US);
Richard K. Everett, Alexandria, VA (US);
Virginia G. DeGiorgi, Nanjejmoy, MD (US);
Andrew B. Geltmacher, Alexandria, VA (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A material test specimen design is taught for the determination of critical strain and stress states for multiaxial fracture. The objective of the specimen is to increase the amount of data obtained per specimen while retaining simplicity in testing procedure by using standard tension testing machines to generate the primary deformation of the specimen. The specimen, in conjunction with analytical or computational simulation, uses nonuniform deformation fields produced by secondary and tertiary strain concentrations to generate and track these multiaxial strain states to fracture. Typically, the primary deformation is uniaxial tension of a panel, the secondary strain concentration is a circular hole in the panel and the tertiary strain concentrations are areas of reduced thickness within the deformation field of the circular hole. Multiaxial strain ratios from −0.50 to −0.10 and control over fracture initiation sites may be generated by a test specimen design of the type taught by this invention.